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' ARC LAMP. No. 325,802. Patented Sept. 8, 1885.

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UNITED STATES PATENT OFFICE.

GEORGE M. HOPKINS, OF BROOKLYN, NEW? YORK.

Aao LAMP.

SPEQIFIGATION forming part of Letters Patent No, 325,802, dated September 9, 1885.

Application filed October 27, 1894.

T0 aZZ whom it may concern:

Be it known that I, GEORGE M. Hornins, of Brooklyn, in the county of Kings and State of New York, have invented a new and useful Improvement in Are Lamps, ofwhich the following is a specification, reference being had to the annexed drawings, in which- Figure 1 is a side elevation showing the essential features of my invention, and Fig. 2 is a horizontal section taken on linexocin Fig.1.

The object of my invention is to provide simple and efficient means for forming and regulating the are in arc lamps; and it con sists in an electro-magnet having cores extended beyond its coils and slot-ted to receive the carbon-supporting rod, and in an armature pivoted at one end to a spring supporting it within the field of the magnet, and pro vided with an arm reaching into the slot in one of the poles, and carrying a foot-piece for hearing against the carbon-supporting rod, and pressing it against a roller contained by the slot in the core of one of the arms of the magnet, the opposite end of the armature being held by a spring away from the other pole of the magnet, but within the weaker portion of the magnetic field.

An ordinary U electro-magnet, A, rigidly supported with its yoke 13 in a vertical position, has its poles a b prolonged beyond the ends of the coils and slotted vertically to receive the positivecarbonholding rod 0. The slot in the upper magnetcore extends within the coil, and a roller, 0, is pivoted therein in position to touch the earbonholding rod 0 as it slides up and down in the slots in the cores of the magnet. The armature D is pivoted at its upper end in ears (I, projecting from a spring, E, secured to a fixed support, F, and an arm, 6, projecting from the face of the armature D into the slot in the upper core of the magnet is provided with a foot, f, jointed thereto, so that it will move with the said'arm e. The lower end of the armature D is drawn away from the magnet-core B by a spring, G, which is secured to an adjustingscrew, g,passing through a fixed support, h, and provided with a milled nut, z. The support F of the spring E is provided with an arm, j, which projects downward over the spring, and is tapped to receive an adj LlStlDg-SOI'GW, 7c,which turns against the spring E, and is employed (h'o model.)

to regulate the tension of the said spring. The carbon'holding rod 0 is provided with a socket, H, for receiving the positive carbon I, and the lower or negative carbon, J, is held by a fixed support axially in line with the positive carbon I.

When no current passes through the magnet A, the carbon points I and J are in con tact, and the spring E withdraws the armature D from the upper core of the magnet A and removes the footf from the face of the carbon-holding rod C; but when a current is passed through the magnet A the first result is to attract the upper end of the armature D against the tension of the spring E and bring the footf against the face of the carbon-holding rod 0, pressing the said rod against the roller 0. The lower end of the armature D, being within the influence of the core of the lower half of the magnet, is now attracted toward the said core, turning the armature on its pivot in the spring E, and by virtue of the friction of the foot f on the rod 0 raising the said rod so as to form the are between the carbons I J As the are is lengthened by the burning away of the carbon the current gradually becomes weakened and the lower end of the armature D is gradually released, allowing the spring G- to retract and turn the armature on its pivot on the spring E, and carrying the carbonrod holderG slowly downward, feeding the carbon and maintaining the are. The burning away of the carbon now lengthens the arc, and the current becoming weakened the magnetism of the cores of the magnet is diminished, and the upper end of the armature D is released, when the retractile force of the springE draws the armature away from the core of the upper half of the magnet, removing the foot f from the carbon-rod holder O, allowing it to drop, when the are becoming suddenly shorter the strength of the magnet is renewed, and the upper end of the armature D is again drawn toward the magnet, clamping the carbon-rod holder 0 against the roller a, holding it until the arc is again shortened, when the operation just described is repeated.

If at any time during the normal working of the lamp the current should be strengthened in the circuit in which it is placed, the lower end of the armature will be drawn toward the core of the lower half of the magnet-A, turning the armature on its pivot, raising the arm 6 and foot f, thus carrying up the carbon-rod holder 0, and elongating the are.

5 Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In an electric-arc lamp, the combination of an electro-magnet having prolonged and i slotted cores, a carbon-holding rod passing through the slots of the magnet-cores, an armature pivoted near one end to a movable support and provided with an arm and clamping-foot, and a spring adapted to draw the free I end of the armature away from the magnet,

substantially as herein shown and described.

2. The combinatiomin an electric-arc lamp,

of the elect-ro-magnet A, carbon-holding rod 0, armature D, provided with the arm 6, the

clamping-footf, supportingspring E, and the spring G, substantially as herein described.

3. In an electric-arc lamp, the combination,

with the armature D, having the arm 0, and a foot for pressing the carbon-holding rod, of a supportingspring, E, pivoted to the arma tnre, and capable of drawing it away from the core of the magnet when the current passing through the lamp is diminished, and a regulating-screw, 7r, for adjusting the tension of the spring E, as and for the purpose specified. o

4. The combination, with the magnet-core a, carbon-holding rod 0, and clamping device for holding the rod 0, of a roller, 0, journaled in the slot in the magnet-core, and adapted to guide the rod O,and receive the lateral press- 5 ure thereof when the rod is clamped, substantially as described.

5. In an electric-arc lamp, an electro-magnet, and a lever-armature having its ends nor mally in magnetic fields of different strength, the pivoted end of the lever-armature being provided with a clamping device adapted to hold the carbon-holding rod, the free end of the lever-armature being provided with a spring acting in opposition to the magnet,the said lever-armature being adapted to swing by the action of the magnet or its spring to form or vary the are, as herein specified.

GEO. M. HOPKINS.

Witnesses:

DAVID K. CASE, H. O. HAGEN. 

